Question

6. Qual é o ângulo formado entre as retas r: 2x-y-5=0 e s:3x+y+1=0 é:
a. 45°
b. 90°
c. 0°
d. 30°
e. 1°

Answer 1

3x+y+1=0 => y=-3x-1=> m=-3

2x-y-5=0 => y=2x-5 ==> a=2

tgx = m-a/1+m.a

tgx = -3-2/1+(-3).2

tgx = -5/1-6

tgx = -5/-5

tgx = 1 ==> x= 45° ✓